In Orthodontics it is very important to have knowledge of the sizes of the teeth. In general, size is expressed by the mesiodistal diameter, that is, from one side to the other of the tooth seen from the front.
Knowing the proper size of each tooth allows you to know the space that each one of them needs to be able to align correctly in the arch.
The Bolton index is one of the many existing indexes and refers to the discrepancy between the available space in the arch and the size of the teeth. The Bolton index calculation is considered a very effective procedure when diagnosing tooth space discrepancies in permanent or permanent dentition.
Bolton analysis
Bolton determined that approximately 5% of the population has a discrepancy in the size of their teeth.
East Bolton analysis consists of a analysis of the previous proportion, designed to identify incompatibilities in anterior teeth. Or, in the analysis of the proportion of total dentition, which when compared to the anterior proportion, determines the discrepancies of the lateral or posterior teeth. In this way, it offers a method to determine the tooth size discrepancy and its effects on the relationship between the upper and lower arch.
Thus, the Bolton index determines the proportion between the sum of the diameters of the twelve lower teeth (from first molar to first molar) and the sum of those same diameters of the same upper teeth, known as Total ratio or Total Bolton. As well, it allows to obtain the proportion between the sum of the widths of the six most anterior upper and lower teeth, known as Previous relationship or Previous Bolton.
This index of the study of Bolton proportions is evaluated using standardized tables for the comparison of the relation of the previous and total proportion, by means of which we can determine if the anomaly is based on the sector previous or in the segments lateral of the dental arch.
Probably, it is one of the most difficult and important appraisals in the diagnosis of Orthodontics. However, it is an important aspect to take into account for the study and the correct assessment of the most appropriate orthodontic treatment for each case.